diff options
| -rw-r--r-- | kernel/reduction.ml | 5 | ||||
| -rw-r--r-- | pretyping/evarconv.ml | 10 |
2 files changed, 11 insertions, 4 deletions
diff --git a/kernel/reduction.ml b/kernel/reduction.ml index e9be1b35d..b3e689414 100644 --- a/kernel/reduction.ml +++ b/kernel/reduction.ml @@ -269,8 +269,9 @@ let convert_constructors_gen cmp_instances cmp_cumul (mind, ind, cns) nargs u1 u if not (Int.equal num_cnstr_args nargs) then cmp_instances u1 u2 s else - let csts = get_cumulativity_constraints CONV cumi u1 u2 in - cmp_cumul csts s + (** By invariant, both constructors have a common supertype, + so they are convertible _at that type_. *) + s let convert_constructors ctor nargs u1 u2 (s, check) = convert_constructors_gen (check.compare_instances ~flex:false) check.compare_cumul_instances diff --git a/pretyping/evarconv.ml b/pretyping/evarconv.ml index 0a63985bf..3c8acb1a7 100644 --- a/pretyping/evarconv.ml +++ b/pretyping/evarconv.ml @@ -530,8 +530,14 @@ and evar_eqappr_x ?(rhs_is_already_stuck = false) ts env evd pbty UnifFailure (evd, NotSameHead) else begin - let evd' = check_leq_inductives evd cumi u u' in - Success (check_leq_inductives evd' cumi u' u) + (** Both constructors should be liftable to the same supertype + at which we compare them, but we don't have access to that type in + untyped unification. We hence enforce that one is lower than the other. + Note the criterion is more relaxed in conversion. *) + try Success (check_leq_inductives evd cumi u u') + with Univ.UniverseInconsistency _ -> + try Success (check_leq_inductives evd cumi u' u) + with Univ.UniverseInconsistency e -> UnifFailure (evd, UnifUnivInconsistency e) end end in |